Pakowki Lake: Risks and Pressures

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Pakowki Lake is fed by intermittent streams, and as such. it is particularly susceptible to drought conditions and its productivity has declined in recent years due to prolonged drought. Landscape pressures mirror those of other regions and are primarily related to agricultural development (drained wetlands, cultivation of native grasslands, altered shorelines); and oil and gas exploration and development.

Conservation:

Alberta Wilderness Association (AWA) has classified a “Pakowki Lake Area of Concern” of approximately 380 square kilometres in this sub-basin, contiguous with two other AWA Areas of Concern: Milk River–Sage Creek and Cypress Hills. AWA considers this area to be of national environmental significance and they include the intermittent lake itself, as well as the surrounding prairie uplands and a large sand dune–wetland complex which includes extensive bulrush marshes.

AWA concerns centre on the fact that Pakowki Lake is an important staging area for migrating shorebirds and provides a nesting area for birds that occur in few other places in Canada. The AWA also states that the area is important for rare and uncommon plants found in the sand dune and wetland habitats. Significant, rare or uncommon plants within this sub-basin include Western Spiderwort (nationally threatened), Smooth Goosefoot (nationally vulnerable), Great Basin Downingia (nationally rare), Sand Nut-grass, and Annual Skeletonweed.

Interesting fauna found at the site include Pronghorn Antelope – especially in key habitat areas along the east shore – and the rare Plains Hognose Snake. Most other animal species found in this sub-basin are common throughout the entire watershed.

Avian Botulism:

One of the major threats to the waterfowl using Pakowki Lake is outbreaks of avian botulism, a naturally occurring food poisoning that affects many bird species – primarily waterfowl and shorebirds – throughout the world. Although any water body used by waterfowl is a potential site for botulism, some lakes have a history of recurrent problems and Pakowki Lake has suffered extensive waterfowl losses in the past. The disease struck from 1994 to 1997, and according to Bird Studies Canada, in 1995 alone 100,825 dead birds were collected including Green-winged Teals, Northern Pintails, Northern Shovelers and Mallards.

Drought and climate change:

The entire region is historically subject to drought, and rivers within the SSRB are considered to be some of the most climate change sensitive and vulnerable watersheds in Canada. Because Pakowki Lake is fed by intermittent streams it is particularly susceptible to drought conditions and its productivity has declined in recent years due to prolonged drought.

Landscape Modification:

Landscape pressures in this sub-basin mirror those of other sub-basins and are primarily related to agricultural development (drained wetlands, cultivation of native grasslands, altered shorelines); and oil and gas exploration and development. Livestock activity, recreation and pipeline crossings have affected the integrity of river and stream banks within the sub-basin, and oil and gas activity is high throughout the region. Oil and gas development impact the landscape through road construction, alteration of native habitat and introduction of invasive species. Seismic testing has indicated the presence of Nisku oil in the Pakowki Lake – Manyberries area and recommendations have been made for “more detailed” seismic evaluation.